an apostle is basically a piece of paper from government sort of confirming that yes this is your real birth certificate..
just go to the court house with your birth certificate where you would normaly get birth certificates and stuff.. and say you need it to be apostled. it takes a couple of weeks,

or you can request a new copy and say that you need it to be apostled, I was able to do this online, and pay an extra 5$ but that was for the state of texas, i dont know where you where born though..